Robin Soderling will miss the Australian Open as he battles to recover from illness, the 13th-ranked Swede said.
Soderling, twice a French Open finalist, has been suffering from the viral infection mononucleosis and has not played since he won in Bastad last July.
"My recovery has been longer than expected. I am feeling better with each day but it will still take some time before I can start practicing in full speed," Soderling said in a post on his Twitter account.
"My goal is to start with practice in January and I hope for tournament comeback in February but at this stage it is hard to know when and where.
"I hope my body will allow me to do that."
The former world number four made the fourth round at Melbourne Park earlier this year, after never passing the second round in five previous appearances.
The 2012 Australian Open runs from Jan. 16-29.